The present invention relates to apparatus including a prism or prisms for viewing a scene, and to a method of color photography using such apparatus.
It has long been recognized that a prism may be used to demonstrate the color components of light by dispersing the light. The dispersion of a beam of sunlight is a familiar demonstration to beginning students of optical physics. Various apparatus have been provided for using prisms for other purposes, in addition to demonstration of light dispersion.
Jordan, U.S. Pat. No. 3,468,599, provides a viewing apparatus comprising a pair of prisms, intended for viewing black and white television. Light passing through and dispersed by the prisms enters the eyes of the viewer, to provide some coloration of the image. The apparatus comprises an elongated box, having a pair of chambers, in each of which is a right-angle prism, having an objective face and an ocular face, these faces diverging downwardly. A color filter is placed over part of the objective face of the prisms to provide a "soft rose color", the filter being smaller than the objective face to permit the passage of some light through the prisms without passage through the filter. The viewer is required to tilt the apparatus at an angle to the horizontal, and to look upwardly, in order to view a television screen which is generally directly in front of the viewer.
Stricker, U.S. Pat. No. 3,475,079, provides a viewer mounted on a post and which contains a prism within a housing, the housing having appertures located on opposite sides. A scene may be viewed through the prism, with change in the appearance due to chromatic aberration caused by the prism.
Wingate, U.S. Pat. No. 2,123,682, provides an attachment for a pair of glasses which includes a prism in advance of each of the lenses. The purpose is to enable a person to lie on his back and to view a scene horizontally, caused by internal reflection within the prism.
Color photography is widely used, not only for aesthetics, but for instructional and scientific purposes. From the point of view of aesthetics, photographers have used color films of different characteristics and, optionally, have used color filters in order to achieve desired artistic effects of the photographs which are produced. In the instructional and scientific fields, color photography is used in order to provide enhanced information from the scenes or objects photographed. In both fields of endeavor, the photographer uses his knowledge, obtained through education and experience, to select the particular films and filters which he judges will be those which will best produce the desired results. In doing this work, the photographers often use color filters both to view the scene prior to making the photograph on the color-sensitive film and to filter the light from the scene or object before it reaches the color sensitive film.
The above methods, while producing aesthetic and artistically appealing photographs and informative instructional and scientific photographic reproductions, do not fully achieve their goals due to the fact that it is not possible, when viewing unrefracted light, to gain all possible information about the composition of the light from the scene or object, and particularly the dominant colors thereof.